Answer:
B. The observational study is a cross-sectional study because information is collected at a specific point in time.
Step-by-step explanation:
1) There are three types of Observational Studies: Case-control, cross-sectional and Cohort.
2) Since the researchers collected information from those 1800 adults at a certain time, then we can call it a cross-sectional study. It does not provide solid results since the research was not done over a period to collect further information. We don't know, for example, much more than what that association deeply mean.
3) If we wonder more, then the researchers would have to track those adults over a given period, i.e. a Cohort would be necessary.
4) Moreover, it's not "retrospective" for virtually every question, always makes us look back somehow, and it does not categorize a kind of observational study.
Using a proportional relationship, the amounts are given as follows:
<h3>What is a proportional relationship?</h3>
A proportional relationship is a function in which the output variable is given by the input variable multiplied by a constant of proportionality, that is:
y = kx
In which k is the constant of proportionality.
For this problem, we have that:
- The input variable is the number of tennis players.
- The output variable is the number of soccer players.
From the first row of the table, the constant is given as follows:
k = 35/15 = 7/3.
Hence the relationship is:
y = 7/3x.
For the second row of the table, we have that x = 3, hence:
y = 7/3 x 3 = 7.
For the third row of the table, we have that y = 84, hence:
84 = 7/3x
x = 84 x 3/7
x = 36.
Then the amounts are given as follows:
More can be learned about proportional relationships at brainly.com/question/10424180
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Answer:
it is c
Step-by-step explanation:
